Pflügers Archiv

, Volume 429, Issue 6, pp 873–875 | Cite as

Irreversible and reversible blockade of IMR32 calcium channel currents by synthetic MVIIA and iodinated MVIIC ω-conopeptides

  • James A. Fox
Short Communication Neurophysiology, Muscle and Sensory Organs


The actions of two ω-conopeptides on high-voltage-activated calcium channel currents in differentiated human neuroblastoma IMR32 cells were investigated. Similar to the previously reported action of ω-conopeptide GVIA, ω-conopeptide MVIIA irreversibly blocks IMR32 HVA calcium channel currents at low concentrations. Unlike GVIA action, however, novel w-conopeptide SNX-260 (iodinated MVIIC) reversibly blocks these currents, also at low concentrations, with an IC50 near 50 nM. Different ω-conopeptides may be potent blockers of HVA calcium channel currents yet act either reversibly or irreversibly in a single cell.

Key Words

Calcium Channel ω-conotoxin IMR32 


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Copyright information

© Springer-Verlag 1995

Authors and Affiliations

  • James A. Fox
    • 1
  1. 1.Axon Instruments Inc.Foster CityUSA

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